SQLSERVER存储过程查找数据表中某列存在空值

CREATE PROCEDURE [dbo].[PRO_CHK_COLUMNS_VALUES]
	-- Add the parameters for the stored procedure here
	 @TableName nvarchar(50) ,
	 @column_name  nvarchar(50) OUTPUT
AS
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from
	-- interfering with SELECT statements.
	SET NOCOUNT ON;
	-- Declare the return variable here
	DECLARE @list_column_name nvarchar(50)
	DECLARE @sql nvarchar(1000)
　　DECLARE @count int

　　declare cur cursor for --定义游标		
    select name from sys.columns  where object_id=OBJECT_ID(''+@TableName+'')
    open cur--打开游标  
	fetch next from cur into @list_column_name --把提取操作的列数据放到局部变量中  
	while(@@fetch_status=0) --游标读取下一条数据是否成功  
		begin
	    SET	@sql='select @count = COUNT(1) from '+@TableName +' where '+@list_column_name +' is null  '
	    exec sp_executesql @sql,N'@count nvarchar(50) out ',@count out 
				if @count > 0
					begin
						 SELECT @column_name=@list_column_name
						 break
					end
		   fetch next from cur into  @list_column_name --读取下一条数据记录放到局部变量中，变量的数目必须与游标选择列表中的列的数目一致  
		
		end    		
	close cur--关闭游标  
	deallocate cur--删除游标 

END